Amyotrophic Lateral Sclerosis (ALS), Spinal Bulbar Muscular Atrophy (SBMA), and Spinal Muscular Atrophy (SMA) are motor neuron diseases (MNDs) characterised by progressive motor neuron degeneration, weakness and muscular atrophy. Lipid dysregulation is well recognised in each of these conditions and occurs prior to neurodegeneration. Several lipid markers have been shown to predict prognosis in ALS. Sphingolipids are complex lipids enriched in the central nervous system and are integral to key cellular functions including membrane stability and signalling pathways, as well as being mediators of neuroinflammation and neurodegeneration.
Condition | Gene | Affected Enzyme/Protein | Effect on Sphingolipids | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Sphingolipid synthesis | ||||||||||
Juvenile ALS [92][18] HSAN1 [93][19] |
SPTLC1 | SPT | Atypical deoxysphingolipids, cannot be converted into complex SLs or degraded | |||||||
Bovine SMA [106][24] | 46 | FVT1 | KSR | Reduced ceramide synthesis from de novo pathway | ||||||
] | 161 ALS 117 Controls |
Plasma | GC/MS and UPLC-MS/MS | 335 lipids, proteins and carbohydrates | ↑: LPC (16:1) and SM (18:0) | Not evaluated | ALS type 8 [107][25] Late onset SMA [108][26] |
VAPB | VAPB with effect on CERT and FAPP2 | Impaired transfer of ceramide and glucosylceramide from ER to golgi apparatus |
Cutler et al. 2002 [16][10] | 9 ALS 3 Control |
Spinal cord | ES/MS/MS | Sphingolipids, Phospholipids, Cholesterol Esters, and Lipid Peroxides |
↑: Cer (C16:0), Cer (C24:0), SM (C16:0), CE (C16:0) and CE (C18:0) | Not evaluated | ALS [96][22] | SGMS2 | SMS2 | Affects sphingomyelin synthesis |
Sphingolipid degradation | ||||||||||
SMA-PME [91][17] Farber’s disease [109][27] |
ASAH1 | Acid ceramidase | Ceramide accumulation | |||||||
GM1 gangliodosis [110][28] | GLB1 | β-Galactosidase | GM1 ganglioside accumulation | |||||||
GM2 gangliodoses [110 | ||||||||||
Goutman et al. 2020 [127][47] | 125 ALS 71 Controls |
Plasma | UPLC-MS/MS | 899 metabolites | ↑: 8 Cers, 28 DAGs, 5 HEXC, 24 SMs, | Not evaluated | ||||
↓: 5 DAGs, 5 SMs | ][28] | |||||||||
Goutman et al. 2022 [128][48] | Above cohort of 125 ALS and 71 controls with 2nd cohort 225 ALS, 104 controls | Plasma | UPLC-MS/MS | 640 metabolites | SM most significant sub-pathway LCFA, acyl intermediates and Cers also raised |
SM (d18:1/24:0), SM (d18:1/20:0, d16:1/22:0), SM (d18:1/14:0, d16:1/16:0) and lignoceroylcarnitine (C24) correlated with ALSFRS-R |
| |||
Bjornevik et al. 2019 [90][15] | 275 ALS 549 Controls |
Plasma | LC/MS | 404 metabolites | ↑: SM (C18:2), PC (C40:7), PC (C38:4), CE (C22:4) | Not evaluated |
|
|||
↓: 12 TAGs, | HEXA HEXB |
DAG (C36:1), DAG (C36:2), PC (C36:2), 21-deoxycortisol, butyrobetaine |
|
GM2 ganglioside accumulation GM2 ganglioside, glycolipid GA2 and globoside accumulation |
||||||
Fabry’s Disease [111][29] | GLA | α-Galactosidase A | Globotriaosylceramide accumulation | |||||||
Metachromatic Leukodystrophy [112][30] | ARSA | Arylsulphatase A | Sulfatides accumulation | |||||||
Niemann-Pick Disease [113][31]
|
SMPD1 NPC1/NPC2 |
Sphingomyelinase | Sphingomyelin accumulation | |||||||
Gaucher’s Disease [114][32] | GBA | Glucocerebrosidase | Glucosylceramide accumulation | |||||||
Krabbe’s Disease [115][33] | GALC | Galactosylceramidase | Galactosylceramide accumulation |
Study | Patients | Sample Type | Quantification Platform | Metabolites Evaluated | Lipid Changes in MND | Prognostic Use |
---|---|---|---|---|---|---|
Blasco et al. 2017 [125][45] | 40 ALS 45 Controls |
CSF | HRMS | 122 lipids | ↑: PC (36:4p), PC (36:4e), SM (d43:2), SM (d34:0) | Higher SM (d43:2) and lower TG (16:0/16:0/18:1) and TG (18:0/16:0/18:1) had slower progression |
↓: TG (16:1/18:1/18:2) | ||||||
Lawton et al. 2012 [126][ | ||||||
Lawton et al. 2014 | ||||||
[ | ||||||
122 | ||||||
] | ||||||
[ | ||||||
49] | 172 ALS 73 neurological mimics 50 Controls |
plasma | GC/MS and UPLC-MS/MS | 367 metabolites | ↑: SM (d18:1/16:0), 5 FAs, 3-dehydrocarnitine, 1,2-propanediol, Chol, 1-stearoyl-GPI |
1,2-propanediol correlated with ALSFRS-R |
Chang et al. 2021 [129][50] | 36 ALS 36 Controls |
plasma | LC–MS/MS | 185 metabolites | ↑: SM (C24:1), SM (C20:2), PC (C44:5), PC (C34:2) | 14 PCs and (OH) SM(C22:1) correlated with ALSFRS-R |
↓: (OH) SM(C22:1) (OH) SM(C24:1) 29 other PCs |
||||||
Fernandez-Eulate et al. 2020 [130][51] | 20 ALS 20 Controls |
Serum | UPLC-MS | 416 lipids | ↑: SM (39:1), SM (33:1), PE (P-20:1/0:0), PE (O-16:0/0:0), 5 PCs, androsterone, etiocholanolone and 2 FAs |
Not evaluated |
Blasco et al. 2018 [116][43] | 74 ALS | Plasma | HPLC-MS/MS | 188 metabolites | Not evaluated—no control participants | SM (C22:3) and SM (C34:1) correlated with disease progression, SM (24:1), SM (C16:1) and (OH) SM (C22:2) correlated with SVC |
Dodge et al. 2015 [131][52] | 6 ALS 6 Control |
Spinal cord | LC-MS/MS | Cer, SM and GSLs | ↑: Cer (C18:0), Cer (C24:1), (OH) Cer (C24:0), Cerebroside (C18:0 and C24:1), GlcCer (C18:0 and C24:1), LacCer (18:0), GL3 (C22:1), GM3 (C23:0), GM1 (C18:0) AND SM (C18:0) | Not evaluated |
Sol et al. 2021 [132][53] | 23 ALS 10 Controls |
CSF Plasma |
LC-MS/MS | 1018 lipids in plasma and 843 in CSF | ↑: 3 Fas, 2 DAGs, 13 TGs, 17 GPLs, 3 Cer, 1 SM | Fast vs. slow progressors had increased- 1 FA, 4 GLs, 4 GPLs, 2 Cer, 1 GM3, and decreased- 46 GLs, 36 GPLs, 2 Cer, 8 SM, 5 CE |
↓: 2 DAGs, 4 GPLs, 3 Cer, 3 GLs | ||||||
Area-Gomez et al. 2021 [133][54] | 40 ALS 28 PLS 28 Control |
Serum/Plasma | LC/MS | 532 lipids | ↑: Cer, LacCer, CE | SM declined and Cer increased at follow up |
↓: SM, PC, PS |